1. Field of the Invention
This invention relates generally to the field of water purification, and more specifically to an apparatus and process for recovering metals from aqueous solutions by passing an aqueous solution, which contains dissolved metals (e.g., gold, silver, iron, aluminum, platinum, uranium, etc.) through a very high voltage electric field accompanied by a very small trickle current charge to enhance adsorption, polarization, ion exchange or otherwise agglomerate the metal and then, filtering, adsorbing, exchanging or otherwise separating the metal from the water.
2. State of the Prior Art
The removal of impurities and contaminants, including dissolved metals, from water has long been an important issue due to both environmental and public health concerns, and there are industrial interests in processes for capturing and recovering dissolved metals from aqueous solutions. Many devices and processes have thus been designed to treat contaminated water in order to make it safe for consumption or other public use. Metals of all types (e.g., gold, silver, iron, aluminum, platinum, uranium, selenium, and arsenic, etc.) dissolved or suspended in water comprise one such category of impurities, and commonly end up in the effluent wastewater of mining, city water discharge or other industrial operations including, most recently, from the semiconductor industry, as well as from many other industrial processes, commercial products, and natural sources, such as soils and groundwater aquifers. There are many known processes for removing metals from an aqueous solution. For example, electrodeposition processes, in which suspended or dissolved metals in an electrolyte are deposited onto an electrode by electrolysis are common. However, these known electrodeposition processes become very inefficient and cease to be cost effective when applied to aqueous solutions containing low concentrations of metals, which is often the case, especially in environmental clean-up and water purification applications. There are other processes for removing metals from aqueous solutions, such as chemical reactions to precipitate compounds, use of flocculents, adhesion to activated carbons and other materials, and the like, but such processes are also expensive, require substantial quality controls, and have their own recovery and disposal problems.